1. Field of the Invention
The present invention relates generally to attachments for machine tools. More particularly, the invention concerns a stop device for use in connection with vertical milling machines to control vertical travel of the quill mechanism of the machine.
2. Discussion of the Invention
Vertical milling machines are of course old in the art and a number of different types of milling machines are readily commercially available. These commercially available milling machines may be generally classified into two main divisions, horizontal and vertical. In horizontal milling machines the milling cutter is carried on a horizontal arbor (spindle), while in the vertical type milling machine the arbor is vertically disposed.
Typically vertical milling machines are built up from a massive casting, Usually a rectangular box section forming an upright column which supports a vertical spindle that carries a rotating multi-toothed cutter. The upright column also supports an adjustable, power-driven, horizontal table which supports the work and controllably feeds it relative to the rotating spindle in a direction generally perpendicular to the axis of the spindle. Vertical milling machines are typically used for facing and boring and are sometimes provided with a rotary table for making cylindrical surfaces.
The rotating spindle of the vertical mill is typically carried by a quill which is controllably moveable in a vertical direction relative to the supporting column by a hand feed lever. Movement of the hand feed lever moves the quill and the cutting tool vertically relative to the work piece and to the work piece supporting table. Many commercially available vertical milling machines are provided with an automatic stop which can be used to control vertical travel of the quill of the machine. As will be better understood from the discussion which follows, the stop device of the present invention comprises a bolt-on, hard-stop unit that can be used in connection with most commercially available vertical milling machines without removing the existing automatic stop mechanism. More particularly, the device of the present invention includes mounting means for mounting the device on the vertical milling machine at a location approximate the quill mechanism of the machine. A guide shaft, which is disposed between and connected to the mounting means, supports a plurality of adjustable stops which can be used to precisely control vertical movement of the quill assembly of the vertical milling machine. Each of the adjustable stops is slidably movable relative to the guide shaft of the device and can be quickly and easily positioned by the operator to precisely control manually the extent of vertical travel of the quill mechanism of the milling machine.